A number of methods are currently available for culturing cells from human tumors in order to determine their response to chemotherapeutic agents. Each one has problems associated with it. The goal of this research is to perfect a primary tissue culture method which we have developed for cultivation of human tumor cells taken at biopsy or excision and to apply the method to predict pretherapy sensitivity of the tumors to potential anticancer agents. The methodology takes advantage of the fact that cells from various tissues can be cultured on the surface of collagen-coated tissue culture dishes, in the absence of serum, but with proper, specific supplementation of the medium with hormones and trace metals. Samples of the tumors are cleaned, minced and placed in single cell suspension by enzyme treatment. The enzymes are removed by washing the cells with medium. The tumor cell suspension is immediately plated onto collagen treated petri dishes (1.5 ml/35 mm dish). The dishes are kept in an incubator at 37 C. Two days after seeding, the tumor cells in replicates are incubated with drugs of potential clinical use for 1 hour or longer at 37 C in an incubator. The controls are given mock drug treatment. After incubation the drugs are removed and the cells are allowed to proliferate. Population development in both control and drug treated dishes is followed quantitatively by counting the cell nuclei with a Coulter counter. In the first studies, colon and lung tumors from patients will be cultured and their responses to 13 specific anti-neoplastic agents will be assessed. The efficacy of the primary tissue culture method will be determined by comparing the response in that assay system to the response of the same tumor cells to the same spectrum of drugs in the clonogenic assay, and, in some cases to the response in the nude mouse. The primary tissue culture method has several advantages over other methods. Results of the chemotherapy response will be known in less than 10 days, as opposed to 2 to 3 weeks for the clonogenic assay and 2-3 months for nude mouse assay. Subcultivation and continued propagation of tumor cells is possible whereas this cannot be accomplished with the clonogenic assay. Drug combinations and schedules can be studied although this cannot be accomplished with the clonogenic assay, since the medium in the soft agar cannot be changed. The primary tissue culture includes the full spectrum of cells which are present in the growing tumor, not just a subset selected for clonogenic survival in soft agar.